In Phonon there are three main concepts: MediaObjects, Paths and Outputs.
The MediaObjects control the playback/capture and provide the media data.
MediaObjects can be connected to Outputs using Path objects which also
allow the insertion of Effect objects between MediaObject and Output.

Log message:
phonon{,-qt5}: update to 4.10.1
4.10.1
Fixes cmake-level compatibility issues with Qt 5.11 for libphonon and
the backends.
4.10.0
Centred around improving behavior with VLC 3.0
which introduced new API allowing correct roles being set on
PulseAudio streams and as a result notification volume control is now
actually working as expected. This also means automatic corking of
music streams on voice calls can work correctly.